Scientists have developed the first room-temperature, electrically driven, topological laser, which could be useful in telecom wavelength applications. The novel device is made up of a 10 by 10 grid of 30 micron-wide rings. Small oblong rings around 5 microns wide connect these rings to one another. All these rings consist of a sandwich of layers of semiconductors, such as indium gallium arsenide, indium phosphide and indium gallium arsenide phosphide.
The 10 by 10 grid of rings in the novel topological laser served as multiple coupled resonators. The rings generate laser light at a wavelength of 1.5 microns, which is the most common wavelength (telecom wavelength) utilized in fiber optic communications, when electrodes at the array’s edge electronically pump this grid.
The size and shape of the rings, their position in relation to one another, and the thicknesses and composition of the semiconductor layers all contribute to the topological protection of the laser’s light. Topological photonics has enabled the shaping of interconnection between multiple resonators, allowing for new and improved functionality.